Graduate Students Seminar two

Title: Computability-Theoretic Properties of (2,1):1 Structures
Speaker: Hakim Walker
Abstract: A (2,1):1 structure consists of a countable set A (usually the natural numbers) and a function f which maps, to each element of A, either exactly one element of A or exactly two elements of A. Similar structures have been studied recently by Harizanov, Cenzer, Remmel, and Marshall, particularly the complexity of isomorphisms between such structures. We will begin this talk with a brief overview of computability theory, then discuss some preliminary results, and conclude with an application to the Collatz conjecture.
Note: The Graduate Student Seminar is mandatory for ALL graduate students!